This invention relates to a method for producing alkaline earth halophosphate stir-in phosphors in larger volumes than have been previously produced by a method in which conditions such as particle size of the starting calcium monohydrogen phosphate, and milling time are controlled and in which the final sifting of the phosphor is done by a unique technique which involves non-shearing action.
Up to this time alkaline earth halophosphate phosphors were produced using mechanical vibratory screening technology in which the screens had to be cleaned often due to build up of phosphor material thereon. This was disadvantageous because it was very labor intensive and inefficient. Losses of large amounts of phosphor were due to dusting and cleaning of the screens.